The present invention relates to a double-axle drive for a track-bound, electric self-propelled vehicle in which the electric propulsion motor is arranged longitudinally between two driving axles of the vehicle.
U.S. Pat. No. 4,130,065 discloses a double-axle drive longitudinally arranged between two driving axles in which the otherwise customary end bells of the electric propulsion motor are eliminated since the rotor shaft is supported in the pinion bearings of an angle or miter transmission and therefore in the transmission housing. This results in considerable weight savings. In order to compensate for displacements of the rotor in the longitudinal drive, a centering coupling is disclosed in U.S. Pat. No. 4,130,065 which permits at least some longitudinal displacement in the vehicle of the rotor shaft. Additional weight reductions can be achieved by providing the propulsion motor without a housing.
DE-AS No. 26 06 807 discloses the desirability of providing the dual output electric propulsion motor as a double motor to introduce flexibility to meet different operating conditions which sometimes include different speeds of the two driving axles. The double motor disclosed in DE-AS No. 26 06 807 comprises two electrically independent rotors of equal length and a common stator comprised of two separate stator lamination stacks of equal length and a continuous stator winding. In such a double motor, the two rotors are subjected to a common, electrically undivided excitation, and a clean separation of the fluxes of both rotors is obtained. Thereby, unambiguous magnetic decoupling is provided. The equal length rotors have the same speed/torque characteristic and can rotate at different speeds so that compulsion forces caused by slippage phenomena due to differences in wheel diameters or when negotiating curves are not generated. The rotors are supported by a central shaft surrounded by an independent hollow shaft, where the central shaft mechanically couples the rotors to each other.